Protests took place in cities across the United States and beyond on Friday to denounce President Donald Trump’s missile strikes on Syria.

The strikes on a Syrian air base—launched without congressional approval or U.N. authorization—were said to be in retaliation for Tuesday’s chemical weapons attack against Syrian civilians, though there has not yet been an independent investigation showing that the chemical attack was, as the U.S. claims, ordered by President Bashar al-Assad.

While the direct military attack against the Syrian government elicited fawning praise from media and lawmakers on both sides of the aisle, peace groups and humanitarian voices have condemned them, and many hit the streets to say that “bombs are not the answer” to the country’s ongoing conflict.

In Philadelphia, dozens of protesters marched against the strikes, with some carrying signs reading “U.S. Out of the Middle East.”

In New York City’s Union Square, protester said Martin Jennings said to NBC New York: “It’s only going to escalate the violence,” adding: “I’m really concerned about the future of the Syrian people.”

In Chicago, protester Vicki Cervantes stated to CBS, “The tragedy of the children is heart-rending,” possibly referring to the children killed in the chemical attack or those killed in ongoing coalition strikes. “But I think the response of escalation—of more bombing, of more war—only means more dead children.”

In Detroit, Joe Mchahwar, son of a Syrian native, helped organize a protest and told MLive.com: “Even if international law is broken in a place, we’re not some vigilante, rogue power that should just be allowed to go attack anyone that they deem has broken the law.”

Across the Atlantic, the British Stop the War Coalition held what it called an “emergency protest” Friday evening at Downing Street, saying the missiles launched by Trump “will only increase the level of killing in Syria, and inflame the terrible war that has already caused untold misery for the people of the country.”

​​”This is the worst possible way to respond to the indefensible attack at Khan Sheikhun. As well as ​deepening​ the tragedy of the Syrian people, ​this utterly​​ irresponsible act ​threatens to widen the war and lead the West into military confrontation with Russia,” the group stated.

Earlier on Friday, during a U.N. Security Council meeting—in which the Bolivian ambassador to the United Nations offered a vital history lesson—U.S. Ambassador to the U.N. Nikki Haley, who “seemed to be channeling George W. Bush even more than her actual boss,” according to one observer, described the strikes as “a very measured step.”